last but not least to cap off your build Rylai's Crystal Scepter, giving hp and because of your high armor and mr increasing your effective health by quite alot.

Skilling Order

Max turrets first, taking one point in your grenade then maxing rockets as your secondary skill

Summoner Abilities

Exhaust + Flash, no substitue

Exhaust both keeps them near your turrets and reduces the amount of damage they do, this can result in you gaining alot of kills because melee will over commit to a fight and not be able to escape.

Exhaust is OP, take it and abuse it.

Flash because Flash is OP, allowing you to blink rocket kill someone or blink over a wall for a quick escape.

Heimers turrets and YOU

I see alot of people who play Heimer not place his turrets effectively, so heres a list of rules to follow with turret placement.

1. Turrets in brush are OP because enemy's cannot auto attack them without getting into there range, however this only applies if they are not firing, so careful position is important, when laning in the bottom or top lanes, place them in the brush closest to your tower, and then either sit in the brush closest there tower, OR place a ward here, enemy champions will not be able to touch your turrets with out you being able to effectively counteract them.

2. Only ever have one offensive turret, that is, only ever have one turret on the frontlines attacking creeps, why? having a defensive turret is MASSIVELY important because when you need to escape that turret will always start attacking an enemy champion, allowing you to reliably pop your ultimate and slow them, even better once they have chased you this far, exhaust and counterattack them, they will run and the two turrets will now finish them off.

3. Turrets Hold Creep Aggro, what does this mean? you can pull minions in lane away from the creep line, i.e you can pull them into the river if you want, attacking enemy champions and then getting the creeps to latch onto the turrets will allow you to zone enemy champions massively

4. Remember your turret placement order, doing this can deny the enemy gold from killing your turrets if you place a turret destroying the previous one before it gives them gold, effectively wasting there time at the cost of mana you would have spent placing the turret again anyhow.

5. Cut off enemy escapes, placing turrets along common enemy escape routes before the start of a fight can net you alot of kills when the enemy thinks they can escape easily, i.e kassadin overcommits to a fight and then rifts into your turrets.

Cons
-Not an effective offensive hero due to turrets being static, even with placement on the frontlines it is not advisable as aoe will generally kill them.
-Prone to focus, and easily shutdown without an Hourglass
-Passive is useless past low level laning
-Ultimate Reliant on turrets and as such rarely see's use as an offensive ultimate

Working in the team

Heimer i find is a pretty bad teamfighter due to his reliance on turrets, i find he is much more effective constantly pushing lanes without actually being at the lane. placing turrets inbetween towers and then heading off to the teamfight will usually net you a atower kill as the lane is starved of enemy creeps and so gets pushed, aslong as you pop your ultimate to keep the towers alive this tactic is fairly sound. he does however bring a strong stun/blind that you can use to protect your ranged AD carry from melee focus, also using your missiles to pop escaping enemy's is extremely effective.

Useful and useless at the same time, you'll be using it more for the heal when you solo dragon/ push a lane inbetween towers then the slow, however the slow is useful early game when laning as a suprise gotcha! move, however dont rely on it late game as most melee can ignore this and still chase you due to blinks .ect